The Clinical Hematology Research Career Development Program is a Harvard-wide initiative to support training in clinical research for non-malignant hematology. The long-term objective of the program is to attract and retain talented young physician scientists to the field of blood diseases. Current trends in adult hematology/oncology careers are toward oncology. This K12 scholars'program is aimed at reversing that trend. This proposed program is a joint effort of six primary Harvard-affiliated institutes and hospitals with major training and research programs in non-malignant hematology (alphabetically, Beth Israel Deaconess Medical Center (BIDMC), Brigham and Women's Hospital (BWH), Center for Blood Research Institute (CBRI), Children's Hospital, Boston (CHB), Dana Farber Cancer Institute (DFCI), and Mass. General Hospital (MGH)). The administrative home of the program is at CHB. The principal investigator is a pediatric hematologist with a track record of clinical research mentoring and active involvement in NHLBI clinical research networks. The site directors from the member hospitals are distinguished hematologists with strong track records in hematology research. More than 40 potential mentors are available, covering all of the project disciplines. Scholars in the K12 program will receive formal didactic training in responsible conduct of research, in clinical areas of non-malignant hematology, and in methodology for patient-oriented research. Masters programs of Harvard Medical School available for the latter training are (i) a K30-funded Scholars in Clinical Sciences Program;(ii) Program in Clinical Effectiveness (a joint program with the Harvard School of Public Health), and (iii) Clinical Investigator Training Program offered jointly by BWH, BIDMC, HMS and MIT. The initiative includes the major clinical areas of: aplastic anemia/bone marrow failure syndromes;hemoglobinopathies including sickle cell disease and thalassemia;hemophilia and other hemostatic disorders;venous thromboembolism and thrombophilias;myelodysplastic syndromes and myeloproliferative disorders;transfusion medicine, including unique aspects of pediatric transfusion medicine. Together, the member institutions host more than 7,000 annual ambulatory hematology visits. Clinical research resources include three NHLBI clinical trials networks, four large GCRCs, sub-contract sites for the Boston Cooperative Sickle Cell Center, the Boston Hemophilia Center, and the resources of the DFCI/Harvard Cancer Center. An advisory committee composed of specialists in each key area, representing all six institutes/hospitals will oversee the project and serve as the admissions committee. Scholar Applicants will be drawn primarily from among the training programs at the member hospitals in Hematology/Oncology and Transfusion Medicine. Typically trainees will spend two years as scholars, pursuing an independent research project along with their didactic training. A colloquium series in non-malignant hematology will bring together scholars, their mentors, program faculty and other hematologists from around the Boston Hematology community. Formal annual evaluation of the program and of trainees'progress will be used for ongoing program improvements.